Hydraulic jack



Dec; 6, 1949 M. SIMART 2,490,284

HYDRAULXC JACK Filed Sept. 4, 1945 2 Sheets-Sheet 1 1 NVEN TOR MARSH/44L 57/14/127;

M. SIMART HYDRAULIC JACK Dec. 6, 1949 2 Sheets-Sheet 2 Filed Sept. 4, 1945 m N A m 5 M M w M Y E N m T A ram in projected position.

' Patented Dec. 6, 1949 UNITED STATES PATENT OFFICE 3 Claims.

My invention relates to hydraulic devices particularly adapted, although not necessarily, for use as pullers for removing gears and the like from shafts, and while my invention will be described herein and is illustrated in the accompanying drawings as incorporated in a pulling device, its structure and mode of operation lends itself to use as a pushing device such for example as a hydraulic jack.

It is a purpose of my invention to provide a. hydraulic pulling device for gears and the like, which is characterized by its structural simplicity and low cost of manufacture, and by its shortness in overall length as compared to similar devices which greatly facilitates its manual operation and permits its use in places inaccessible to other hydraulic devices.

It is also a purpose of my invention to provide a hydraulic pulling device embodying a ram constructed to provide a reservoir for the Pressure fluid employed, and a simple means, devoid of springs, which is automatically operable to insure the required circulation of fluid from the reservoir to a point exteriorly of the ram for hydraulically projecting the ram.

A further purpose of my invention is the provision of a hydraulic pulling device embodying a. pump the cylinder of which can be actuated to open a release valve and allow return of fluid to the reservoir incident to retraction of th ram.

I will describe only one form of hydraulic" the line 33 of Fig. 2.

Fig. 4 is a view similar to Fig. 2 showing the Fig. 5 is a plan of the lever mounting sleeve of Fig. l, on the same scale as Fig. 4.

to similar The ram includes a cylinder l5 slidably fitted in the casing K so that the casing and the cylinder are axially movable relatively. On the outer end of the ram cylinder is a head IS in the form of a screw plug which may be of the construction shown in Fig. 2 and which is adapted to engage the end of the shaft for removing a gear therefrom, as will be more fully described hereinafter.

To seal the joint, between the ram cylinder, and the casing against fluid leakage, a stuifing box S is carried by the end of the casing. This box, in the present instance, comprises a. collar I1 and washers l8, preferably of leather, which are fitted within a recess I9 in a head 20 of the casing K. The collar is screw-threaded in the head 20 to confine the washers against displacement and to cause them to form a seal about the ram to prevent the escape of fluid.

The head 20 is formed to provide an annular shoulder 2|, which functions as an abutment or seat for a ram carrying frame, as will be more fully described hereinafter.

The interior of the ram cylinder 15 provides a fluid reservoir chamber I50. the ends of which are defined by the outer head [6 and an inner head I611, the latter being an integral part of the cylinder and slightly spaced from the inner wall of the casing K. Within this chamber I50. a piston F is slidable axially and, in the present instance, such piston is made up of a pair of reversely disposed leather cups 22 secured one to the other by a bolt 24 carrying washers 23. This piston is designed to function as a follower for the fluid contained in the chamber, and this following action is permitted by the provision of a vent port 25 in the head 16, as will be more fully described later herein.

has its inner end screwthreaded as at 3| in the ram head Ilia, so that by screwingor unscrewing it within the head the release valve 29 can be actuated to close or open the port 2'I.' Radially disposed ports 32 are provided in the ram ,head

- lfia, these portsleading from the port 21 to a fluid pressure chamber 33 formed between the inner end of the ram cylinder I5 andthe confronting conical wall 340i the casing K.

By virtue of the threaded connection 3| between the ram head Ilia and the pump cylinder 30, the pump cylinder is movable axially withthe ram, and to provide for such movement and at the same time prevent the escape of the pressure fluid from the chamber 33, the casing K is constructed to receive a conventional stuiling box B made up of a'leather packing ring 36, metal ring 3'1, and a nut 38 threaded in the casing K.

One the inner end of the pump cylinder a plug 39 is threaded therein. This plug is provided with a port 40 controlled by a ball check valve 4!, and in such manner that fluid can flow upwardly butnot downwardly through .the port. The pump cylinder at a point beyond the head 16a is formed with an outlet port 43 controlled by a ball valve 44 so that fluid may flow outwardly. from the cylinder into the chamber 33 but not inwardly of the cylinder. in closed position by a plate 45 .(Fig, 3) con nected to the ends of a coil spring 46 seated in a groove 4! formed in the pump barrel 30;.

The pump P includes a rod piston or plunger This ball valve. issheld.

48 movable axially therein and sealed against the escape of fluid from the cylinder by a stuffing box 49 which is of conventional construction. This rod piston is adapted to be manually.reciprocated by a lever 59 mounted on a frame 51. The frame is in the form of a split sleevewith its lower end receiving the upper end of thepump cylinder 30, and securely clamped thereto by a stud 52 extending through cars 53 formed on the sleeve. The rod piston 58 extendsupwardly into the sleeve i, where it is provided with a head 54 grooved as at 54a to receive the opposite ends of the pin 55 on the lever 56; One end of the lever is pivoted by a pin 56 extending through ears 51 on the upper end of the sleeve 5! so that by rocking of the lever reciprocation of the rod piston 48 can be effected. This pin 56. is removable from the ears 5? to allow detachment of the lever 50 when required.

In the adaptation of my invention to the gear puller it is necessary to provide some means. for operatively connecting the casing K to the gear so that upon operation of theram R. the gear will be pulled from the shaft upon whichit is mounted. Such means may consist. of acollar 58 mounted on acasing K to abut the shoulder 2|. This collar is provided with radial extensions 59 on which are mounted arms 50 having hooks 6| engageable with the gear 52 on the shaft 83. The arms 60 are mounted on the extensions, by bolts 63 and to permit the necessary adjustments of the arms on the extensions both longitudinally and laterally, the extensions and arms may be provided with a plurality of openings 64; ferreception of the bolts B3,.as will be understood;

The operation of the device is as follows:

With the ram R in retracted positionas shown A in Fig. 2 the piston F is at theouterend of the reservoir chamber a, the pressure fluid formerly contained in the pressurecham-ber 33 -having been returned to the chamber. [5a through opening of the valve 28. To open. the portZ'lands thus place the ports 32 into communication with the port 21 'so that the fluid can flow fromthe chamber 33 into the chamber 15a, the operator can, by pulling the pump cylinder ilfi outwardly to its fullest extent, cause the ;head- Ita;- to m ove to its inner-most position. Under return-of the fluid to the reservoir chamber the pist n ;F -is forced outwardly toward the, heael i 6,, the port permitting .of. this because it permits the :expulsion. of air from the :ranrto atmgsphere To project the ram R fromth e casing K, and to thereby exercise a pulling action onthe arms 60 to effect removal of the gearfiZ- from the shaft 63, the rod piston 48 is reciprocated by the lever to pump fluid from the reservoir into. the pressure chamber 33. Upon outward movement of the rod piston suction is produced in the pump cylinder to open the valve 4| and suck oil from the reservoir into the cylinder. Upon inward movement of the rod piston the fluid in the cylinder is actuated to close the valve M and to project the ram froriirthe casing to ultimately remove the gear 82 from the shaft 63.

During the operation the piston F, by reason of the vent port 25, is free to and does follow the fluid in the reservoir. In this manner the length and area of the reservoir decreases automatically as the fluid is-drawn therefrom, and so as to maintain that space between the piston and the inner end of the ram completely filled with fluid. Thus under the fluid withdrawing action of the pump there can at no time be formed in the reservoir a space devoid of fluid to render the pump inoperative.

To permit retraction of the ram following its operation to remove. the gear 62, the operator merely unscrews the pump cylinder until the release valve 29 is unseated from the port 21, when the chambers lfia and 33 are placed in communication with each, other to permit return of the fluid to the chamber l5a under retractive move- .ment of the ram by pulling outwardly on the pump cylinder.

By virtue of forming the fluid reservoir within the ram itself, the overall length of the device as a whole is greatly-reduced over previous devices, and as a result of this shortening the device is lessbulky, may be more readily operated, and may be positioned in places normally inaccessible to hydraulic devices of great length. Also, by forming the release valve on the inner end of the pump cylinder it is possible to actuate this valve through the pump cylinder, thereby facilitating retraction of the 'ramandwithout the necessity of employing a separately operable release valve.

Although I have herein shown and described only one form of hydraulic device as incorporated in a gear puller, it is to be understood that my device is capable of being incorporated in a pushing device such for example as a hydraulic jack, without departing from the spirit and scope of vmy invention and the scope of the appended claims.

I claim:

1. In a hydraulic device of the character described: a tubular casing; a ram slidable in one .-end of said casing; a pump slidable in the other end of said casing; saidram being hollow to provide therein a fluid reservoir chamber, and said ram and casing constructed to provide a fluid pressure chamber at the inner end of said ram;

*2. release port and communicating release ducts in the inner end portion of said ram; said port communicating with said reservoir chamber, and said ducts communicating with 'said pressure chamber; said pump including acylinder and a piston; a release valve on; said cylinder for said port, and ;said cylinder threaded in said ram to actuate said valve; aninlet port in said cylinder leading from; sa id; reservoir chamber to said cylinder; anputlet port in said cylinder leading from the latter to said pressure chamber; check valves for said inlet and outlet ports; apiston in said reservoir chamber; a head-closing the outer end of said ram; and a vent port in said head.

2.;In ahydraulic device of th kind described: a-tubular casing having one end of increased outward diameter, a peripheral shoulder being provided by said portion, and having the opposite end decreased ininward diameter; atubular ram slidable in said casing with one end working outwardly through the end of the casing of increased outward diameter, a sealing gland being arranged in said casing end engaging against the surface of said ram; a head closing the inner end of said ram, a fluid pressure chamber being provided between the end of decreased diameter of the casing and the head of the ram; av piston provided with oppositely directed cup washers workin within said tubular ram, the space between said piston and the ram head providing a hydraulic fluid reservoir, the opposite side of the piston being open to atmospheric pressure; an elongated pump cylinder mounted at its inner end in said head closing the inner end of the ram and rotationally adjustable therein and extending outwardly through the end of the casing of reduced internal diameter; a valve structure permitting hydraulic fluid to flow into the pump cylinder through the ram head but preventing flow of fluid in the reverse direction; a second valve structure permitting fluid to flow from the pump cylinder into the fluid pressure chamber but preventin flow of the fluid in reverse direction; a release valve structure controlled by the rotational adjustment of the pump barrel in the ram head to permit fluid to return from the pressure chamber through the ram head to the fluid reservoir; and a reciprocable piston in said pump cylinder; load engaging elements mounted on said peripheral shoulder; and a head closing the outward end of the ram having an unobstructed air passage formed therein.

3. In a hydraulic device of the kind described: a tubular casing reduced in diameter at one end; a tubular ram eXtendable through the end of the casing and having a head closing its inner end; a pump cylinder extending through the reduced 6 diameter end of the casing in fluid tight sliding contact therewith and threaded into the head closing the inner end of the ram; a floating piston mounted in said tubular ram and constituting a movable wall; a reservoir of fluid carried in said ram between said movable wall and the head closing the inner head of the ram; a passage way through said ram head controlled by manipulation of the pump cylinder to enable fluid from between said ram head and the reduced diameter end of the casing to flow into said reservoir; valve means enabling fluid to flow into said pump cylinder from the reservoir and out of the pump cylinder into the space between the ram head and the reduced diameter end of the casing, said valve means being effective to prevent reverse flow of the fluid; a reciprocable pump plunger in said pump cylinder and extending outwardly therefrom; and a head mounted on the outward end of the ram and formed to admit atmospheric pressure to the outer side of said floating piston.

MARSHALL SIMART.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Liddell et a1 Aug. 22, 1939 

